Patent EA-003241-B1 (EA)
Title: Wellbore system including a conduit and an expandable device
Inventor: HEIJNEN WILHELMUS HUBERTUS PAU
IPC: E21B41/00
Filed: 1999-11-01
Abstract: 1. A system including a conduit having a longitudinal axis, and a device which is radially expandable relative to the conduit from a retracted mode whereby the device is radially spaced from the conduit, to an expanded mode whereby the device is radially expanded against the conduit, wherein the device includes a shape memory metal element transformable from a first shape to a second shape upon reaching a selected temperature, the shape memory metal element being arranged to expand the device from the retracted mode to the expanded mode upon transformation of the memory metal element from the first shape to the second shape, wherein said conduit is one of an outer conduit, and the system further comprises an inner conduit extending coaxially into the outer conduit, conduit whereby an annular space is defined between the outer conduit and the inner conduit, the device is adopted to locate and retract it from the annular space, wherein the shape memory metal elements are made in the form of rods, which, when retracted in an axial direction, act upon the sealing rings via wedges, providing metal-to-metal seal. 2. The system of claim 1, wherein the expandable device forms a sealing device arranged in said annular space, which sealing device in the radially expanded mode thereof is expanded against said inner conduit and against said outer conduit. 3. The system of claim 2, further including a branched wellbore system formed in an earth formation, the branched wellbore system comprising a main wellbore provided with a main casing, a branch wellbore provided with a branch casing, and a casing junction member having a main bore and a branch bore in fluid communication with the main bore, the main bore being an extension of the main casing, the branch bore being an extension of the branch casing, and wherein said inner conduit is formed by the branch casing and the outer conduit is formed by the branch bore. 4. The system of claim 3, wherein the earth formation includes a hydrocarbon fluid reservoir zone, an overburden layer located above the reservoir zone and a cap rock layer located between the reservoir zone and the overburden layer, and wherein the casing junction member is located in the overburden layer. 5. The system of claim 3 or 4, further including a secondary conduit extending through said main casing and into said branch bore in a sealing relationship with the branch bore. 6. The system of claim 5, wherein the secondary conduit is one of a hydrocarbon fluid production conduit and a service conduit into which a wellbore tool for performing an operation in the branch wellbore extends. 7. The system of claim 6, wherein the secondary conduit is a service conduit through which a drill string extends so as to further drill the branch wellbore. 8. The system of any one of claims 2-7, wherein the sealing device in the retracted mode thereof is radially spaced from the outer conduit and from the inner conduit. 9. The system of any one of claims 2-8, further including a centralising device arranged in the annular space for centralising the inner conduit within the outer conduit. 10. The system of claim 9, wherein the centralising device is radially expandable from a retracted mode in which the centralising device is radially spaced from at least one of the outer and inner conduits, and an expanded mode in which the centralising device is radially expanded against the inner conduit and against the outer conduit so as to centralise the inner conduit within the outer conduit, the centralising device including a secondary shape memory metal element transformable from one shape to another shape upon reaching a selected transition temperature and being arranged to expand the centralising device from the retracted mode to the expanded mode thereof upon transformation from one to another shape. 11. The system of any one of claims 2-10, wherein the sealing device in the expanded mode thereof provides a metal-to-metal seal between the inner conduit and the outer conduit. 12. The system of any one of claims 1-11, wherein the device includes a wedge shaped expander being arranged to radially expand the device upon a selected axial movement of the expander, and wherein the memory metal element is arranged to induce said selected axial movement to the expander upon transformation of the memory metal element from the first shape to the second shape thereof. 13. The system of claim 1, wherein the device is an anchoring device arranged within the conduit and adapted to be anchored to the inner surface of the conduit when in the radially expanded mode. 14. The system of claims 13, wherein said conduit forms part of a wellbore system formed in an earth formation. 15. The system substantially as described hereinbefore with reference to the drawings.